Seviper’s swordlike tail serves two purposes—it slashes foes and douses them with secreted poison. This Pokémon will not give up its long-running blood feud with Zangoose. Constant polishing makes the edge of the blade on its tail extremely sharp. It’s Zangoose’s archrival. In battle, it uses its bladed tail to counter any Zangoose. It secretes a deadly venom in its tail.
Pokédex entry #336
Seviper is a type poison Pokémon that doesn't evolve
Seviper in Pokémon GO
It's possible to hatch Seviper from an egg?
No, Seviper can't be hatched.
Which are Seviper’s strengths and weaknesses?
Seviper is a poison type Pokémon. poison type pokémons are strong against grass, bug, fairy pokémons but weak against poison, ground, rock, ghost pokémons. They are not affected by steel type pokémons.